Peripheral zone prostate-specific antigen density: an effective parameter for prostate cancer prediction in men receiving 5α-reductase inhibitors

5-alpha reductase inhibitors and MRI prostates: actively reducing prostate sizes and ambiguity

BACKGROUND

Magnetic resonance imaging (MRI) scans are increasingly first-line investigations for suspected prostate cancer, and essential in the decision for biopsy. 5-alpha reductase inhibitor (5-ARI) use has been shown to reduce prostate size and prostate cancer risk. However, insufficient data exists on how 5-ARI use affects MRI findings and yield of biopsy. This study explores the differences in imaging and prostate cancer diagnoses between patients receiving and not receiving 5-ARI therapy.

METHODS

From 2015 to 2020, we collected retrospective data of consecutive patients undergoing prostate biopsy at one centre. We included patients who were biopsy-naïve, had prior negative biopsies, or on active surveillance for low-grade prostate cancer. Clinical and pathological data was collected, including 5-ARI use, Prostate Imaging Reporting and Data System (PIRADS) classification and biopsy results.

RESULTS

351 men underwent saturation biopsy with or without targeted biopsies. 54 (15.3%) had a history of 5-ARI use. On mpMRI, there was no significant difference between the 5ARI and non-5-ARI groups in PIRADS distribution, number of lesions, and lesion location. Significantly fewer cancers were detected in the 5-ARI group (46.3% vs. 68.0%; p < 0.01). There were no significant differences in PIRADS distribution in 5-ARI patients with positive and negative biopsy.

CONCLUSION

Our study found significant differences in biochemical, imaging and biopsy characteristics between 5-ARI and non-5-ARI groups. While both groups had similar PIRADS distribution, 5-ARI patients had a lower rate of positive biopsies across all PIRADS categories, which may suggest that the use of 5ARI may confound MRI findings. Further studies on how 5-ARI therapy affects the imaging characteristics of prostate cancer should be performed.

New Diagnostic Model for Clinically Significant Prostate Cancer in Biopsy-Naïve Men With PIRADS 3

Purpose

The aim of this study was to explore a new model of clinical decision-making to predict the occurrence of clinically significant prostate cancer (csPCa).

Patients and Methods

The demographic and clinical characteristics of 152 patients were recorded. Prostate-specific antigen (PSA), PSA density (PSAD), adjusted PSAD of peripheral zone (aPSADPZ), and peripheral zone volume ratio (PZ ratio) were calculated and subjected to receiver operating characteristic (ROC) curve analysis. The calibration and discrimination abilities of new nomograms were verified with calibration curve and area under the ROC curve (AUC). The clinical benefits of these models were evaluated by decision curve analysis and clinical impact curves.

Results

The AUCs of PSA, PSAD, aPSADPZ, and PZ ratio were 0.521, 0.645, 0.745, and 0.717 for prostate cancer (PCa) diagnosis, while the corresponding values were 0.590, 0.678, 0.780, and 0.731 for csPCa diagnosis, respectively. All nomograms displayed higher net benefit and better overall calibration than the scenarios for predicting the occurrence of csPCa. The new model significantly improved the diagnostic accuracy of csPCa (0.865 vs. 0.741, p = 0.0284) compared with the base model. In addition, the new model was better than the base model for predicting csPCa in the low or medium probability while the number of patients with csPCa predicted by the new model was in good agreement with the actual number of patients with csPCa in the high-risk threshold.

Conclusions

This study demonstrates that aPSADPZ has a higher predictive accuracy for csPCa diagnosis than the conventional indicators. Including aPSADPZ, PZ ratio, and age can improve csPCa diagnosis and avoid unnecessary biopsies.

Is PSA density of the peripheral zone as a useful predictor for prostate cancer in patients with gray zone PSA levels?

Background

Serum prostate-specific antigen (PSA) is widely used in screening tests for prostate cancer. As the low specificity of PSA results in unnecessary and invasive prostate biopsies, we evaluated the clinical significance of various PSAs and PSA density (PSAD) related to peripheral zones in patients with gray zone PSA level (4–10 ng/mL).

Methods

A total of 1300 patients underwent transrectal ultrasonography-guided prostate biopsy from 2014 to 2019. Among them, 545 patients in the gray zone were divided into the prostate cancer diagnosis group and the non-prostate cancer diagnosis group, and PSA, relative extra transitional zone PSA (RETzPSA), estimated post holmium laser enucleation of the prostate PSA (EPHPSA), PSAD, peripheral zone PSA density (PZPSAD) and extra-transitional zone density (ETzD) were compared and analyzed using receiver-operating characteristics (ROC) analysis after 1:1 matching using propensity score.

Results

Area under the ROC curve values of PSA, EPHPSA, RETzPSA, PSA density, ETzD, and PZPSAD were 0.553 (95% CI: 0.495–0.610), 0.611 (95% CI: 0.554–0.666), 0.673 (95% CI: 0.617–0.725), 0.745 (95% CI: 0.693–0.793), 0.731 (95% CI: 0.677–0.780) and 0.677 (95% CI: 0.611–0.719), respectively. PSAD had 67.11% sensitivity, 71.71% specificity, and 70.34% positive predictive rate at 0.18 ng/mL/cc. ETzD had 69.08% sensitivity, 64.47% specificity, and 66.04% positive predictive rate at 0.04 ng/mL/cc. When the cut-off value of PSAD was increased to 0.18 ng/mL/cc, the best results were obtained with an odds ratio of 5.171 (95% CI: 3.171–8.432), followed by ETzD with 4.054 (95% CI: 2.513–6.540).

Conclusions

These results suggested that volume-adjusted parameters (ETzD and PSAD) might be more sensitive and accurate than various PSA in gray zone patients who required prostate biopsy to reduce unnecessary biopsy.

Peripheral zone volume ratio (PZ-ratio) is relevant with biopsy results and can increase the accuracy of current diagnostic modality

The current diagnostic modality of prostate cancer based on prostate specific antigen (PSA) and systematic biopsy is far from ideal in terms of over-diagnosing indolent prostate cancer and missing significant ones. Thus we integrated the peripheral zone volume ratio (PZ-ratio) for diagnostic refinement. This retrospective study included 247 consecutive patients who underwent initial transrectal ultrasound-guided systematic prostate biopsy from April 2014 to November 2015. Prostate volume was determined by semi-automatic contour on axial T2 weighted magnetic resonance imaging (MRI). PZ-ratio was inversely correlated with age (r = −0.36, p <0.0001). Adding PZ-ratio and MRI findings to the current predictive model (age, PSA density, percent-free PSA) significantly increased diagnostic accuracy in all patients (AUC: 0.871 vs. 0.812, p = 0.0059), but not in patient subgroup with PSA 4–10 ng/ml (AUC: 0.863 vs. 0.803, p = 0.12). The new model also significantly reduced the number of unnecessary biopsies while missing less significant cancers at a probability threshold of 25%. PZ-ratio is a potential tool in predicting biopsy results, and when added alone or in combination with MRI findings, the diagnostic accuracy can be further enhanced.

Prostate-Specific Antigen Kinetics Following 5α-Reductase Inhibitor Treatment May Be a Useful Indicator for Repeat Prostate Biopsy

PURPOSE

To evaluate parameters for determining repeat prostate biopsy in patients with 5α-reductase inhibitor (5ARI) treatment after initial negative biopsy.

MATERIALS AND METHODS

From January 2007 to December 2015, patients who underwent a repeat prostate biopsy after an initial negative biopsy were enrolled from multiple institutions. Serial prostate-specific antigen (PSA) levels after the initial biopsy were analyzed for PSA kinetics. Clinicopathologic variables were evaluated according to the use of 5ARIs after the initial negative biopsy.

RESULTS

Of 419 patients with initial negative biopsies (median age=67.0 years, median PSA=6.31 ng/mL), 101 patients (24.1%) were diagnosed with prostate cancer at the repeat biopsy. An increase in PSA level at 18 months, compared to that at 6 months, was a predictor of a positive repeat biopsy. However, the use of 5ARIs was not identified as a predictor. Of 126 patients receiving 5ARI treatment after the initial biopsy, 30 (23.8%) were diagnosed with prostate cancer at the repeat biopsy. Increase in PSA level at more than two time points after 6 months of 5ARI treatment (odds ratio=4.84, p=0.005) was associated with cancer detection at the repeat biopsy. There were no significant 5ARI group-related differences in the detection rates of prostate and high-grade cancers (Gleason score ≥7).

CONCLUSION

The effects of 5ARIs on prostate cancer detection and chemoprevention remain uncertain. However, more than two increases in PSA level after 6 months of 5ARI treatment may indicate the presence of prostate cancer.

Prostate specific antigen and acinar density: a new dimension, the "Prostatocrit"

Background

Prostate-specific antigen densities have limited success in diagnosing prostate cancer. We emphasise the importance of the peripheral zone when considered with its cellular constituents, the “prostatocrit”.

Objective

Using zonal volumes and asymmetry of glandular acini, we generate a peripheral zone acinar volume and density. With the ratio to the whole gland, we can better predict high grade and all grade cancer. We can model the gland into its acinar and stromal elements. This new “prostatocrit” model could offer more accurate nomograms for biopsy.

Materials and Methods

674 patients underwent TRUS and biopsy. Whole gland and zonal volumes were recorded. We compared ratio and acinar volumes when added to a “clinic” model using traditional PSA density. Univariate logistic regression was used to find significant predictors for all and high grade cancer. Backwards multiple logistic regression was used to generate ROC curves comparing the new model to conventional density and PSA alone.

Outcome and results

Prediction of all grades of prostate cancer: significant variables revealed four significant “prostatocrit” parameters: log peripheral zone acinar density; peripheral zone acinar volume/whole gland acinar volume; peripheral zone acinar density/whole gland volume; peripheral zone acinar density. Acinar model (AUC 0.774), clinic model (AUC 0.745) (P=0.0105). Prediction of high grade prostate cancer: peripheral zone acinar density (“prostatocrit”) was the only significant density predictor. Acinar model (AUC 0.811), clinic model (AUC 0.769) (P=0.0005).

Conclusion

There is renewed use for ratio and “prostatocrit” density of the peripheral zone in predicting cancer. This outperforms all traditional density measurements.

Indications for a second prostate biopsy in patients suspected with prostate cancer after an initial negative prostate biopsy

BACKGROUND

The present study aimed to evaluate the indications for a second prostate biopsy in patients suspected with prostate cancer after an initial negative prostate biopsy.

METHODS

The present study included 421 patients who underwent repeat prostate biopsy between January 2007 and December 2015 at three hospitals. Clinicopathological data, including patient age, body mass index, history of prostate biopsy, prostate volume, prostate-specific antigen (PSA) level, PSA density, PSA velocity, and PSA fluctuation patterns, were analyzed. The patients were stratified into two groups based on the first PSA pattern (increase/decrease) within 1 year after the initial negative prostate biopsy.

RESULTS

Prostate cancer was detected in 100 (23.8%) of the 421 patients at the second prostate biopsy. In patients with a PSA decrease at the first follow-up, prostate volume and number of increases in the PSA level from the initial prostate biopsy were predictors for prostate cancer diagnosis at the second prostate biopsy. In patients with a steady PSA increase after the initial prostate biopsy, prostate volume and number of biopsy cores were predictors for prostate cancer diagnosis at the second prostate biopsy.

CONCLUSION

The indications for a second prostate biopsy are a low prostate volume and a high number of increases in the PSA level among patients with a PSA decrease at the first follow-up and a low prostate volume and a high number of biopsy cores among patients with a PSA increase at the first follow-up.

Feasibility of robot-assisted radical prostatectomy for very-high risk prostate cancer: surgical and oncological outcomes in men aged ≥70 years

Purpose

Robot-assisted radical prostatectomy with pelvic lymph node dissection (RALP-PLND) is a feasible treatment option for high-risk prostate cancer (HPCa), but remains controversial for very high-risk prostate cancer (VHPCa). We aimed to assess the feasibility of RALP-PLND in men ≥70 years with VHPCa features by comparing outcomes to those of HPCa.

Methods

Among patients aged ≥70 years who underwent RALP-PLND between 2005 and 2012, 101 HPCa patients (31%) (PSA≥20 ng/mL or biopsy Gleason 8–10 or cT3a) and 53 VHPCa patients (16%) (≥cT3b or cN1) were identified. Perioperative, functional, and oncological outcomes were compared between groups.

Results

Perioperative outcomes including operative time (P=0.917), estimated blood loss (P=0.181), and complications (P=0.239) were comparable. Due to Gleason score downgrading, 19% of HPCa and 4% of VHPCa were actually of intermediate risk. VHPCa revealed higher LN involvements (P=0.002). Discrepancy between clinical and pathological nodal status was more frequent in VHPCa (36% vs. 7%, P<0.01). Nodal metastasis would have been missed in 23% patients without PLND, while 13% of cN1 patients were shown to be metastasis-free by PLND. Continence rates were lower for VHPCa (32% vs. 56%, P=0.013). Although biochemical recurrence-free survival rates were comparable (P=0.648), risk for later adjuvant treatments was higher for VHPCa patients (14% vs. 34%, P<0.01).

Conclusions

RALP-PLND is a feasible option for VHPCa in elderly patients with satisfactory oncologic outcomes; however, functional outcomes were not as favorable. Patients who are unable to accept the risk of adjuvant therapy and its side effects or incontinence should be deterred from surgical treatment, and other options such as radiation therapy could be an alternative.